At Wed, 8 May 2013 23:56:51 +0800, Ming Lei wrote: > > On Wed, May 8, 2013 at 2:56 PM, Takashi Iwai <ti...@suse.de> wrote: > > When a system goes to reboot/shutdown, it tries to disable the > > usermode helper via usermodehelper_disable(). This might be blocked > > when a driver tries to load a firmware beforehand and it's stuck by > > some reason. > > IMO, it is better to find why the loading is stuck. Also we already provides > the timeout sysfs file to help to deal with the situation.
The loading is done manually in the case of dell_rbu driver, so it may happen at any time that the f/w loading doesn't finish properly. > > In this patch, the firmware class driver registers a reboot notifier > > so that it can abort all pending f/w bufs. Also enable a flag for > > avoiding the call of usermodehelper after the reboot/shutdown starts. > > With this patch, maybe we only hide the real problem. No, you can simulate the hang easily. Try the below (you can run it on every x86 machine; it just loads the data onto the memory.) - modprobe dell_rbu - echo init > /sys/devices/platform/dell_rbu/image_type (... now /sys/class/firmware/dell_rbu/* appear) - echo 1 > /sys/class/firmware/dell_rbu/loading - halt -p Now the machine gets stuck. Yes, the real problem is obvious: you didn't finish the f/w loading in the above, and it will never happen. This doesn't justify that the machine can be stalled at shutdown, though. Takashi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
